from the southern lexicon; a term for sexually aroused naked-ness. Whereas being naked is simply being nude; being nekked is being nude and ready to fuck.

Billy: Last night, when I got home from the honky tonk, Darlene was laying on the hide-a-bed with a six pack of bud and a can of WD-40--Nekked!
Bob: God-damn.
Billy: I plowed her so hard that, when I donkey punched her, I knocked her ass out!
Bob: Damn, man.
Billy: Yup, she took it harder than The Rock on Smackdown!